Central Florida.

I have been fighting an infestation of very small white insects on my
mandivilla plants. I believe they are mites. They are most prevelant on
the unopened flower buds.

For the past couple of weeks I've been using a systemic product from Ortho
and a insectisodial soap contact treatment.

It seems that many of them have turned from white to brown. Does this mean
the treatments have been working and they are dying? Or is this just their
natural life cycle?

Any suggestions are appreciated.